libexec.xendomains

#!/bin/bash
#
# /etc/init.d/xendomains
# Start / stop domains automatically when domain 0 boots / shuts down.
#
# chkconfig: 345 99 00
# description: Start / stop Xen domains.
#
# This script offers fairly basic functionality.  It should work on Redhat
# but also on LSB-compliant SuSE releases and on Debian with the LSB package
# installed.  (LSB is the Linux Standard Base)
#
# Based on the example in the "Designing High Quality Integrated Linux
# Applications HOWTO" by Avi Alkalay
# <http://www.tldp.org/HOWTO/HighQuality-Apps-HOWTO/>
#
### BEGIN INIT INFO
# Provides:          xendomains
# Required-Start:    $syslog $remote_fs xenstored xenconsoled
# Should-Start:      xend
# Required-Stop:     $syslog $remote_fs xenstored xenconsoled
# Should-Stop:       xend
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start/stop secondary xen domains
# Description:       Start / stop domains automatically when domain 0 
#                    boots / shuts down.
### END INIT INFO

CMD=xl
$CMD list &> /dev/null
if test $? -ne 0
then
	CMD=xm
fi

$CMD list &> /dev/null
if test $? -ne 0
then
	exit 0;
fi

# Correct exit code would probably be 5, but it's enough 
# if xend complains if we're not running as privileged domain
if ! [ -e /proc/xen/privcmd ]; then
	exit 0
fi

# See docs/misc/distro_mapping.txt
if [ -d /var/lock/subsys ]; then
	LOCKFILE=/var/lock/subsys/xendomains
else
	LOCKFILE=/var/lock/xendomains
fi

if [ -d /etc/sysconfig ]; then
	XENDOM_CONFIG=/etc/sysconfig/xendomains
else
	XENDOM_CONFIG=/etc/default/xendomains
fi

test -r $XENDOM_CONFIG || { echo "$XENDOM_CONFIG not existing";
	if [ "$1" = "stop" ]; then exit 0;
	else exit 6; fi; }

. $XENDOM_CONFIG

# Use the SUSE rc_ init script functions;
# emulate them on LSB, RH and other systems
if test -e /etc/rc.status; then
    # SUSE rc script library
    . /etc/rc.status
else    
    _cmd=$1
    declare -a _SMSG
    if test "${_cmd}" = "status"; then
	_SMSG=(running dead dead unused unknown)
	_RC_UNUSED=3
    else
	_SMSG=(done failed failed missed failed skipped unused failed failed)
	_RC_UNUSED=6
    fi
    if test -e /lib/lsb/init-functions; then
	# LSB    
    	. /lib/lsb/init-functions
        if alias log_success_msg >/dev/null 2>/dev/null; then
	  echo_rc()
	  {
	       echo "  [${_SMSG[${_RC_RV}]}] "
	  }
        else
	  echo_rc()
	  {
	    if test ${_RC_RV} = 0; then
		log_success_msg "  [${_SMSG[${_RC_RV}]}] "
	    else
		log_failure_msg "  [${_SMSG[${_RC_RV}]}] "
	    fi
	  }
        fi
    else    
	# emulate it
	echo_rc()
	{
	    echo "  [${_SMSG[${_RC_RV}]}] "
	}
    fi
    rc_reset() { _RC_RV=0; }
    rc_failed()
    {
	if test -z "$1"; then 
	    _RC_RV=1;
	elif test "$1" != "0"; then 
	    _RC_RV=$1; 
    	fi
	return ${_RC_RV}
    }
    rc_check()
    {
	return rc_failed $?
    }	
    rc_status()
    {
	rc_failed $?
	if test "$1" = "-r"; then _RC_RV=0; shift; fi
	if test "$1" = "-s"; then rc_failed 5; echo_rc; rc_failed 3; shift; fi
	if test "$1" = "-u"; then rc_failed ${_RC_UNUSED}; echo_rc; rc_failed 3; shift; fi
	if test "$1" = "-v"; then echo_rc; shift; fi
	if test "$1" = "-r"; then _RC_RV=0; shift; fi
	return ${_RC_RV}
    }
    rc_exit() { exit ${_RC_RV}; }
    rc_active() 
    {
	if test -z "$RUNLEVEL"; then read RUNLEVEL REST < <(/sbin/runlevel); fi
	if test -e /etc/init.d/S[0-9][0-9]${1}; then return 0; fi
	return 1
    }
fi

if ! which usleep >&/dev/null
then
  usleep()
  {
    if [ -n "$1" ]
    then
      sleep $(( $1 / 1000000 ))
    fi
  }
fi

# Reset status of this service
rc_reset

##
# Returns 0 (success) if the given parameter names a directory, and that
# directory is not empty.
#
contains_something()
{
  if [ -d "$1" ] && [ `/bin/ls $1 | wc -l` -gt 0 ]
  then
    return 0
  else
    return 1
  fi
}

# read name from xen config file
rdname()
{
    NM=$($CMD create --quiet --dryrun --defconfig "$1" |
         sed -n 's/^.*(name \(.*\))$/\1/p')
}

rdnames()
{
    NAMES=
    if ! contains_something "$XENDOMAINS_AUTO"
    then 
	return
    fi
    for dom in $XENDOMAINS_AUTO/*; do
	rdname $dom
	if test -z $NAMES; then 
	    NAMES=$NM; 
	else
	    NAMES="$NAMES|$NM"
	fi
    done
}

parseln()
{
    if [[ "$1" =~ '(domain' ]]; then
        name=;id=
    else if [[ "$1" =~ '(name' ]]; then
        name=$(echo $1 | sed -e 's/^.*(name \(.*\))$/\1/')
    else if [[ "$1" =~ '(domid' ]]; then
        id=$(echo $1 | sed -e 's/^.*(domid \(.*\))$/\1/')
    fi; fi; fi

    [ -n "$name" -a -n "$id" ] && return 0 || return 1
}

is_running()
{
    rdname $1
    RC=1
    name=;id=
    while read LN; do
	parseln "$LN" || continue
	if test $id = 0; then continue; fi
	case $name in 
	    ($NM)
		RC=0
		;;
	esac
    done < <($CMD list -l | grep '(\(domain\|domid\|name\)')
    return $RC
}

start() 
{
    if [ -f $LOCKFILE ]; then 
	echo -e "xendomains already running (lockfile exists)"
	return; 
    fi

    saved_domains=" "
    if [ "$XENDOMAINS_RESTORE" = "true" ] &&
       contains_something "$XENDOMAINS_SAVE"
    then
	mkdir -p $(dirname "$LOCKFILE")
	touch $LOCKFILE
	echo -n "Restoring Xen domains:"
	saved_domains=`ls $XENDOMAINS_SAVE`
        for dom in $XENDOMAINS_SAVE/*; do
            if [ -f $dom ] ; then
                HEADER=`head -c 16 $dom | head -n 1 2> /dev/null`
                if [ $HEADER = "LinuxGuestRecord" ]; then
                    echo -n " ${dom##*/}"
                    XMR=`$CMD restore $dom 2>&1 1>/dev/null`
                    #$CMD restore $dom
                    if [ $? -ne 0 ]; then
                        echo -e "\nAn error occurred while restoring domain ${dom##*/}:\n$XMR"
                        rc_failed $?
                        echo -e '!'
                    else
                        # mv $dom ${dom%/*}/.${dom##*/}
                        rm $dom
                    fi
                fi
            fi
        done
	echo -e
    fi

    if contains_something "$XENDOMAINS_AUTO"
    then
	touch $LOCKFILE
	echo -n "Starting auto Xen domains:"
	# We expect config scripts for auto starting domains to be in
	# XENDOMAINS_AUTO - they could just be symlinks to files elsewhere

	# Create all domains with config files in XENDOMAINS_AUTO.
	# TODO: We should record which domain name belongs 
	# so we have the option to selectively shut down / migrate later
	# If a domain statefile from $XENDOMAINS_SAVE matches a domain name
	# in $XENDOMAINS_AUTO, do not try to start that domain; if it didn't 
	# restore correctly it requires administrative attention.
	for dom in $XENDOMAINS_AUTO/*; do
	    echo -n " ${dom##*/}"
	    shortdom=$(echo $dom | sed -n 's/^.*\/\(.*\)$/\1/p')
	    echo $saved_domains | grep -w $shortdom > /dev/null
	    if [ $? -eq 0 ] || is_running $dom; then
		echo -n "(skip)"
	    else
		XMC=`$CMD create --quiet --defconfig $dom`
		if [ $? -ne 0 ]; then
		    echo -e "\nAn error occurred while creating domain ${dom##*/}: $XMC\n"
		    rc_failed $?
		    echo -e '!'
		else
		    usleep $XENDOMAINS_CREATE_USLEEP
		fi
	    fi
	done
    fi
}

all_zombies()
{
    name=;id=
    while read LN; do
	parseln "$LN" || continue
	if test $id = 0; then continue; fi
	if test "$state" != "-b---d" -a "$state" != "-----d"; then
	    return 1;
	fi
    done < <($CMD list -l | grep '(\(domain\|domid\|name\)')
    return 0
}

# Wait for max $XENDOMAINS_STOP_MAXWAIT for $CMD $1 to finish;
# if it has not exited by that time kill it, so the init script will
# succeed within a finite amount of time; if $2 is nonnull, it will
# kill the command as well as soon as no domain (except for zombies)
# are left (used for shutdown --all). Third parameter, if any, suppresses
# output of dots per working state (formatting issues)
watchdog_xencmd()
{
    if test -z "$XENDOMAINS_STOP_MAXWAIT" -o "$XENDOMAINS_STOP_MAXWAIT" = "0"; then
	exit
    fi

    usleep 20000
    for no in `seq 0 $XENDOMAINS_STOP_MAXWAIT`; do
	# exit if $CMD save/migrate/shutdown is finished
	PSAX=`ps axlw | grep "$CMD $1" | grep -v grep`
	if test -z "$PSAX"; then exit; fi
	if ! test -n "$3"; then echo -n '.'; fi
	sleep 1
	# go to kill immediately if there's only zombies left
	if all_zombies && test -n "$2"; then break; fi
    done
    sleep 1
    read PSF PSUID PSPID PSPPID < <(echo "$PSAX")
    # kill $CMD $1
    kill $PSPID >/dev/null 2>&1
    
    echo -e .
}

stop()
{
    exec 3>&2 2> /dev/null
    
    # Collect list of domains to shut down
    if test "$XENDOMAINS_AUTO_ONLY" = "true"; then
	rdnames
    fi
    echo -n "Shutting down Xen domains:"
    name=;id=
    while read LN; do
	parseln "$LN" || continue
	if test $id = 0; then continue; fi
	echo -n " $name"
	if test "$XENDOMAINS_AUTO_ONLY" = "true"; then
	    eval "
	    case \"\$name\" in
		($NAMES)
		    # nothing
		    ;;
		(*)
		    echo -e '(skip)'
		    continue
		    ;;
	    esac
	    "
	fi
	# XENDOMAINS_SYSRQ chould be something like just "s" 
	# or "s e i u" or even "s e s i u o"
	# for the latter, you should set XENDOMAINS_USLEEP to 1200000 or so
	if test -n "$XENDOMAINS_SYSRQ"; then
	    for sysrq in $XENDOMAINS_SYSRQ; do
		echo -n "(SR-$sysrq)"
		XMR=`$CMD sysrq $id $sysrq 2>&1 1>/dev/null`
		if test $? -ne 0; then
		    echo -e "\nAn error occurred while doing sysrq on domain:\n$XMR\n"
		    rc_failed $?
		    echo -n '!'
		fi
		# usleep just ignores empty arg
		usleep $XENDOMAINS_USLEEP
	    done
	fi
	if test "$state" = "-b---d" -o "$state" = "-----d"; then
	    echo -n "(zomb)"
	    continue
	fi
	if test -n "$XENDOMAINS_MIGRATE"; then
	    echo -n "(migr)"
	    watchdog_xencmd migrate &
	    WDOG_PID=$!
	    XMR=`$CMD migrate $id $XENDOMAINS_MIGRATE 2>&1 1>/dev/null`
	    if test $? -ne 0; then
		echo -e "\nAn error occurred while migrating domain:\n$XMR\n"
		rc_failed $?
		echo -e '!'

		kill $WDOG_PID >/dev/null 2>&1
	    else
		kill $WDOG_PID >/dev/null 2>&1
		
		echo -e .
		usleep 1000
		continue
	    fi
	fi
	if test -n "$XENDOMAINS_SAVE"; then
	    echo -n "(save)"
	    watchdog_xencmd save &
	    WDOG_PID=$!
	    mkdir -p "$XENDOMAINS_SAVE"
	    XMR=`$CMD save $id $XENDOMAINS_SAVE/$name 2>&1 1>/dev/null`
	    if test $? -ne 0; then
		echo -e "\nAn error occurred while saving domain:\n$XMR\n"
		rc_failed $?
		echo -e '!'
		kill $WDOG_PID >/dev/null 2>&1
	    else
		kill $WDOG_PID >/dev/null 2>&1
		echo -e .
		usleep 1000
		continue
	    fi
	fi
	if test -n "$XENDOMAINS_SHUTDOWN"; then
	    # XENDOMAINS_SHUTDOWN should be "--halt --wait"
	    echo -n "(shut)"
	    watchdog_xencmd shutdown &
	    WDOG_PID=$!
	    XMR=`$CMD shutdown $id $XENDOMAINS_SHUTDOWN 2>&1 1>/dev/null`
	    if test $? -ne 0; then
		echo -e "\nAn error occurred while shutting down domain:\n$XMR\n"
		rc_failed $?
		echo -e '!'
	    fi
	    kill $WDOG_PID >/dev/null 2>&1
	fi
    done < <($CMD list -l | grep '(\(domain\|domid\|name\)')

    # NB. this shuts down ALL Xen domains (politely), not just the ones in
    # AUTODIR/*
    # This is because it's easier to do ;-) but arguably if this script is run
    # on system shutdown then it's also the right thing to do.
    if ! all_zombies && test -n "$XENDOMAINS_SHUTDOWN_ALL"; then
	# XENDOMAINS_SHUTDOWN_ALL should be "--all --halt --wait"
	echo -n " SHUTDOWN_ALL "
	watchdog_xencmd shutdown 1 false &
	WDOG_PID=$!
	XMR=`$CMD shutdown $XENDOMAINS_SHUTDOWN_ALL 2>&1 1>/dev/null`
	if test $? -ne 0; then
	    echo -e "\nAn error occurred while shutting down all domains: $XMR\n"
	    rc_failed $?
	    echo -e '!'
	fi
	kill $WDOG_PID >/dev/null 2>&1
    fi

    # Unconditionally delete lock file
    rm -f $LOCKFILE
    
    exec 2>&3
}

check_domain_up()
{
    name=;id=
    while read LN; do
	parseln "$LN" || continue
	if test $id = 0; then continue; fi
	case $name in 
	    ($1)
		return 0
		;;
	esac
    done < <($CMD list -l | grep '(\(domain\|domid\|name\)')
    return 1
}

check_all_auto_domains_up()
{
    if ! contains_something "$XENDOMAINS_AUTO"
    then
      return 0
    fi
    missing=
    for nm in $XENDOMAINS_AUTO/*; do
	rdname $nm
	found=0
	if check_domain_up "$NM"; then 
	    echo -n " $name"
	else 
	    missing="$missing $NM"
	fi
    done
    if test -n "$missing"; then
	echo -n " MISS AUTO:$missing"
	return 1
    fi
    return 0
}

check_all_saved_domains_up()
{
    if ! contains_something "$XENDOMAINS_SAVE" 
    then
      return 0
    fi
    missing=`/bin/ls $XENDOMAINS_SAVE`
    echo -n " MISS SAVED: " $missing
    return 1
}

# This does NOT necessarily restart all running domains: instead it
# stops all running domains and then boots all the domains specified in
# AUTODIR.  If other domains have been started manually then they will
# not get restarted.
# Commented out to avoid confusion!

restart()
{
    stop
    start
}

reload()
{
    restart
}


case "$1" in
    start)
	start
	rc_status
	if test -f $LOCKFILE; then rc_status -v; fi
	;;

    stop)
	stop
	rc_status -v
	;;

    restart)
	restart
	;;
    reload)
	reload
	;;

    status)
	echo -n "Checking for xendomains:" 
	if test ! -f $LOCKFILE; then 
	    rc_failed 3
	else
	    check_all_auto_domains_up
	    rc_status
	    check_all_saved_domains_up
	    rc_status
	fi
	rc_status -v
	;;

    *)
	echo "Usage: $0 {start|stop|restart|reload|status}"
	rc_failed 3
	rc_status -v
	;;
esac

rc_exit